Client: Domestic
Our client, a homeowner in Cheltenham, contacted Timberwise to design and install a basement waterproofing solution within their property to prevent water ingress. This property was a corner terraced property of solid brick construction, and was both unoccupied and unfurnished during our inspection. The weather conditions were sunny.
Challenges
Having previously been a retail unit, the basement area had been used as a storage space. As such, the requirements for protecting the basement from water ingress would have been much lower than they are for habitable spaces. Often, a single form of waterproofing, such as cellar tanking, is enough to protect a non-habitable space from ingress.
However, the standards for habitable spaces are much more stringent, and must comply with BS8102:2022, the Protection of Below Ground Structures Against Water Ingress. To bring the basement into compliance with this legislation, it would be necessary to assess the property as well as the ground conditions surrounding it to design the ideal solution for our client.
Observations
Our surveyor began by attending the property to perform a survey of the basement. During this survey, it was evident that the basement had suffered from the effects of moisture ingress for some time.
An observation of the walls revealed several widespread areas of failed plaster and peeling paint. This was believed to be the result of long-term moisture ingress into the basement. Our surveyor confirmed this suspicion by taking readings with an electronic conductivity meter which, while not giving a true reading from plaster, did indicate the presence of damp within the walls.
An inspection further into the basement revealed a separate vault room with similar problems. However, this room also had some areas of visible pooling on the tiled floor, suggesting that the moisture was ever-present within the basement.
Our surveyor also completed a brief inspection of the ceiling joists, which were revealed in some areas where plasterboard had either fallen or was missing. Though this might have suggested damp ingress into the timber flooring above, the timbers were found to be in good condition with normal levels of moisture.
Our surveyor concluded that the basement was likely suffering from groundwater flooding over any specific defect within the property. Due to the failed plaster throughout the basement, they believed that hydrostatic pressure behind the wall had likely caused the previous cellar tanking to fail. They also concluded that condensation would be a valid concern, given a lack of ventilation within the basement void and the ceiling above.
Solutions
To bring the basement to a habitable state, our surveyor designed a basement waterproofing system that would seek to manage the flow of water within the basement, rather than try to stop it from entering entirely. As such, our surveyor recommended the installation of a Type C cavity drained waterproofing system.
Unlike the cellar tanking, a Type A solution aimed at preventing moisture from entering the basement entirely, a Type C solution allows water to flow into the basement naturally. This water is then diverted into channels through a series of waterproof membranes, which can then be pumped off site. This solution not only prevents defects from forming in the masonry from hydrostatic pressure behind the wall, but it also prevents any moisture from entering the habitable space, making it perfect for use in home conversions such as this.
To begin the installation, our technicians first prepared the walls by removing the existing failed plaster. This created a clean area for our technicians to work from. Once cleared, our technicians installed an anti-lime coating to the floors and walls. This would act as a sealant, providing a first layer of protection against moisture ingress.
Next, our technicians installed the drainage system for the basement. To achieve this, they dug perimeter channels at the base of each wall-floor junction. These channels would collect any water ingress into the basement. These channels were directed into a sump chamber, where a sump pump was installed. This would pump any water out of the basement periodically.
Next, our technicians installed a series of cavity membranes, both to the walls and to the floor. These membranes are sealed at every wall-floor junction, providing a waterproof barrier to prevent moisture ingress. Any water would instead run off the membrane, collecting in the previously dug channels at the base of the walls. This membrane could then be finished with any decoration of our client’s choice once our technicians’ work had concluded.
Once completed, a chipboard floor was installed to ensure the membrane could be walked on without risk of damage. Our technicians also performed testing on the jetting ports at each corner, the sump pump, and its alarm system, ensuring that all the systems were working as intended.
Results
Our client was delighted with the design of their basement waterproofing solution, as well as the work performed by our technicians. They were satisfied that the tests performed confirmed the success of the system, and they were happy to begin decorating the room to their preferred finishes, having peace of mind that water could no longer ingress into the room and damage their property.
Do You Want Help with a Basement Waterproofing Solution?
Our dedicated and experienced team in Cheltenham are ready to talk to you about your options for property preservation. Don’t hesitate to call us on 01242 639 472, or you can request a survey online.
